On May 11, 2004, a link to a five-and-a-half-minute video appeared on the Web site Muntada al-Ansar al-Islami, or the Forum of the Islamic Supporters. Announced with the words SHEIKH ABU MUSAB AL-ZARQAWI SLAUGHTERS AN AMERICAN INFIDEL, the video featured the now-notorious beheading of the American contractor Nicholas Berg. Initially sent from a computer that was probably somewhere in Iraq, the video was copied onto Internet sites and within twenty-four hours had been downloaded half a million times. With the slash of a knife, al-Zarqawi had pulled off the most successful online terrorist PR campaign ever.

It was no small feat. A terrorist intent on eluding capture can’t simply walk into an Internet café in Baghdad or Fallujah and broadcast a video of his exploits to the world. Once that video is posted online and recognized for what it is, the site carrying it may get shut down by government officials, private hackers, or host servers hoping to avoid public outcry. And even if none of those things happens immediately, the site may receive so much traffic all at once that it simply crashes. Al-Zarqawi’s success was possible because he had anticipated the importance of the Internet—an increasingly important weapon in the global terrorist arsenal. Which is where “Irhabi 007” comes in.

Irhabi 007—presumed to be a man, because irhabi in Arabic means “terrorist” and refers to a single male—was first observed in 2003, on two jihadi Web sites. The sites focused on how to commit cyber-crimes, and one of them also disseminated pages of a “jihad encyclopedia—a compendium of violence collected by al-Qaeda in Afghanistan that included detailed instructions on how to use agricultural chemicals as weapons of mass destruction. “I don’t know how old he was, or whether he was male or female, but you got the impression of a teenager,” one analyst told me. “Occasionally he used Arabic, but not much, which suggested he might be using a machine translator. He started out as a bit of a loudmouth, one of those cheerleaders who would go around cheerleading global terrorism.”

Those two sites disappeared in 2004, and Irhabi relocated to al-Ansar, the site where the Berg video was posted. In his early days there Irhabi’s skill set seemed limited. He posted links to run-of-the-mill articles in English and Arabic, and translated the English headlines into Arabic. An article about al-Qaeda’s claim of responsibility for the Madrid train bombings was punctuated with a smiley face; the downing of a U.S. helicopter in Baghdad merited the invocation “God is Great!” Irhabi’s enthusiasm, as measured by the abundance of his posts, earned him the computer-generated title of “distinguished member.”

When Irhabi first turned up on the site, a member of the forum suspected that he was accessing Web pages with his personal IP address—a rookie mistake—and warned him to stop. (Every computer on the Internet bears a numerical code, known as an Internet Protocol, or IP, that acts as an “address” for packets of data traveling to and from the host server. An IP identifies the location of a computer, and by extension its owner, just as surely as a return address on an envelope identifies the home of a sender.) Irhabi took the advice and learned fast. Within months he was dispensing advice himself: he provided security tips on how to avoid detection online; distributed anonymizing software that masks a computer’s actual IP address; and emphasized the importance of using a proxy server, which acts as an intermediary between a user and a host server, and can also be used to mask the user’s identity.

Right from the start Irhabi was determined to make himself useful. On the al-Ansar site he posted maps of Israel, Navy SEAL guides on sniper training, CIA manuals on making explosives, and other intelligence that he’d found online, especially if it concerned Iraq. American soldiers stationed in the country had begun writing blogs about their lives there and were posting photos and videos online. Irhabi wanted to mine those blogs for information about U.S. forces in the country—and he realized how effectively that information could be incorporated into the homemade videos that are the lifeblood of online jihadi forums. “I’m looking for soldier footages from within U.S. bases etc.,” he wrote in March 2004. “That’s the fish I want to catch.” (The U.S. military eventually took measures to protect some of the information.) The next month, he pointed a member toward instructions on how to make smoke bombs, and he illegally distributed software on al-Ansar that included tools for hacking, noting that the tools were “quite complex” for “Newbies.” His efforts did not go unrecognized. “The hero,” one member gushed about Irhabi in a typical post. “God salutes you.” To which Irhabi responded, “Hero? I am only half a man now.”